The invention relates to an actuating device for an electrical switch which switches a light on and off during the opening and closing of a door or lid of a motor-vehicle body. The door or lid is closeable by means of a latch, which provides a mechanism for voluntarily switching the switch into a switch-off position and for keeping it in this switch-off position when the door or lid is open.
An actuating device of this general type can be found in German Offenlegungsschrift 2,003,204. There a pressure switch has an actuating tappet which is longitudinally displaceable and, when the door/lid is closed, is held in a switch-off position with the switch contacts separated and, when the door/lid is open, is brought by spring force into a switch-on position, with the switch contacts connected. That is the generally known functioning of conventional door-lid contact light switches.
To voluntarily switch off a light, switchable on and off by means of the switch contacts, and to relieve the vehicle battery when the door/lid remains open for relatively long periods, the actuating tappet can be pulled out of its switch-position by hand. Then, after overcoming a catch, it assumes a stable third position in which the switch contacts are separated once more. The actuating tappet can be returned to its normal switch-on or switch-off position either by hand, or simply "automatically" as a result of the closing of the door/lid.
There are also vehicles (for example, the VW Passat Variant), in which a boot light is switched on and off as a function of the position of a lock latch by means of an electrical switch assigned to the latch. Here too, it is possible for the light to be switched off voluntarily, with the boot lid open - by bringing the lock latch into a closing position. However, to switch the light on again before the boot lid is closed and to avoid damage at the lock when the boot lid is closed, the outer lock handle then has to be actuated to bring the lock latch again into its release position. An automatic return is not possible.
The object of the invention is to develop the actuating device in such a way that it can be used for a switch which per se is to be switched as a function of positions of a lock latch.
According to the invention, this object is achieved by having a switch-actuating lever acting on the switch in response to an opening and closing of a latch mechanism of the lock into a switch-off position and a switch-on position of the switch and wherein one can voluntarily and independently of the latch move the lever into a stable disengaged position to move the switch into its switch-off position, only when the said latch is in the release position.
It is also advantageous if a driver coupling is provided which couples the switch-actuating lever to movements of the latch and which can be actuated manually to transfer the switch-actuating lever into a stable disengaged position up against a stationary stop and hold it in the disengaged position. The driver coupling is then returnable to an operating position by the latch as it moves into its closing position during the closing of the door or lid. The switch-actuating lever is movably arranged in the lock on a lock carrier and is coupled, via the driver coupling (designed as a bistable catch coupling), to a transmission lever, likewise movably arranged on the lock carrier. The transmission lever is driveable by the lock latch when moved into the closing position. During the voluntary manual transfer of the switch-actuating lever into the disengaged position up against a stop, the catch coupling can be reversed from a first-operational-catch position into a second-disengaged-catch position. When the latch is moved into its closing position, the switch-actuating lever is pressed against the stop by the transmission lever and the catch coupling is returned to the first position again. The transmission lever and the switch-actuating lever are designed as pivoting levers which are mounted on a common shaft axle, fixed to the lock carrier, and which are pivotable through a limited angle .alpha. relative to each other. Both the transmission and the switch actuating levers are two-armed. The transmission lever possesses a recess limited by a spring web and the switch-actuating lever possesses a projecting pin, engaging into the recess. The recess forms a limited path of movement for the pin and is arranged at a radial distance from the common shaft of the two levers and extends over the limited angle .alpha.. The spring web has a catch cam which projects into the recess and by which the first and second catch positions of the catch coupling, or of the pin and of the switch-actuating lever, are defined.
The transmission lever is prestressed resiliently against a buffer, which is fixed to the lock carrier, and against which it rests when the latch is in the release position, and from which it can be lifted off via a lever projection and a nose of the latch moving into its closing position.
It is also advantageous if a take-up structure is provided on the switch-actuating lever for applying the manual disengaging force. A handle with a keyhole, axially aligned with the common pivot shaft is provided on the switch-actuating lever.
A force of a spring prestressing the transmission lever to a switch-on position should be higher than the catching force which can be exerted, in order to reverse the catch coupling when the switch-actuating lever is being transferred into its disengaged position.
Another advantageous structure for the interlock would be to have the switch-actuating lever coupled to the latch itself by a driver coupling to be fixed positively by a detent pawl, disengageable both during the transfer of the switch-actuating lever into its stable disengaged position and during movement of the latch into the closing position. Here the detent pawl, fixing the disengaged position of the switch-actuating lever, is movable together with the latch on the same shaft and is also provided for locking the latch in its closing position. The detent can be returned to its detent position after the release of the latch. Under such an arrangement, the driver coupling possesses a spring which prestresses the switch-actuating lever from the latch towards the detent pawl. This spring is weaker than a spring force prestressing the latch toward its release position and keeping it there. The driver coupling is formed by projections on the latch which are, at least, indirectly in positive contact with the switch-actuating lever. The spring is arranged between an abutment of the switch-actuating lever and one of the projections of the latch and prestresses the switch-actuating lever up against the other projection of the latch towards the release position of the latch. Thus, as a result of the deformation of the spring, the switch-actuating lever can be brought (independently of the latch) into its disengaged position fixed by the detent pawl.
It is also advantageous if the switch-actuating lever is provided with a contour which faces the switch and by means of which the switch is switched into its switch-off position just immediately before the latch returns into its closing position. This preferably occurs when the latch, designed as a rotary latch, is only at an angle of 10.degree. away from its closing position.
It is known (German Offenlegungsschrift 3,500,550) to switch an electrical switch indirectly by a detent pawl as a function of positions of a lock latch. There, the switch is integrated into the control of a central locking system. The detent pawl can be disengaged, counter to a spring force by a lock handle. At the same time as the lock latch is released the switch loaded by the detent pawl, is opened. After the lock handle has been let go, the detent pawl returns to its detent position under the spring force and closes the switch once more. A stable disengaged position of the detent pawl is not provided and would even impair the functioning of the mechanism if provided. In the arrangement according to German Offenlegungsschrift 3,500,550, the switch assumes the same switch (on) position in the two end positions of the lock latch. Only in an intermediate pre-catching position of the detent pawl or the lock latch (which should normally not occur) can it be opened permanently.
In contrast to the general state of the art, in which three switch-contact positions--two "off" and one "on"--are necessary, the actuating device according to the invention can advantageously be combined with a customary two position on/off switch.
In an advantageous development, the disengaged position of the switch-actuating lever, when the lock latch is in the release position, corresponds to its operating position when the latch is in the closing position.
In the actuating device according to the invention, the normal relative position between the switch-actuating lever and the latch can be restored automatically in an especially simple way by closing the door or lid.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.